Dyeing process for animal fibers



510mm room, or nocnsr-on-rnn-ram, am, assmu'on manuammamorusnn ester-salts are i e as onto a fiber, and b Patented 1932 UNITED srA'res rarest OFFICE are num Drawing. Application llel December as, use, mm m. mi in a d, December as, me.

' Watersoluble esterlike derivatives (estersalts) of insoluble dyestufis containing quin-- one grou s, these latter being in a reduced form an esterified (see for instance U. S. Patent N 0. 1,448,251) are employed for dyes ing, printing etc. b5 applying such bodies eve oping thecolour by acid oxidation. he said estersalts havelike acidd estuflsan afinit for the animal applied from fiber. Sue an ester salt may an acid bath to wool, silk etcmnd on this latbe developed. by acid oxiter the dyei ma dation (seeiiso Patent No. 1,675,958).

It has been observed that by this last named method it is often 'dillicult to develop the dyeing in a suitable manner. Over-oxidation of the dyestufl or a too strong yellowingof the fiber (wool) caused by the excess. of the oxidizing agentqis very liable to take place, so that dull and loose, to light shades are obtained.

It has now been found that this over-oxida tion of the dyestufi, Y res ively the too strong yellowing of the fi r (wool), when the usual oxidizing agents, such as for in stance bichromate ofpotash, are used,canbe avoided to a geat extent if watersoluble salts of hydrosulp ocyanic acid, such as sulphocyanlde of ammonia, sulphoncyanide of potash, are added tothe developing bath.

Fofcarryingput the improved rocess the stance, they may beIused as swellin agent. 'They may further be used as acid orming substance (see U. S. Patent No. 1,779,305).

In the present process, however, wherein development is carried out in a bath, to which besides the oxidizing agent, acid is added, the hour, boil for hour, and add 2kg. of

by the fol --and kg. of

material a dyebath is pre ared with 0.2

rought on to the her in the ulphocyanides act as bu fl'er substances.

ey prevent overoxidation and are themselves probably destroyed by oxidation.

The improved process may be illustrated it thereto. e

I Examples for wool "(1') a. D ez'ng.--For 100 kilosof woolen material a yebath is prepared with 0.2 kg. of estersalt of leucotetrabromindigo sultphate of ammonia. Enter at 40 C., raise to e boil in hour, boil for hour, add acetic acid in or' er to exhaust the yebath, boil for a further hour and let cool down.

I Developmenaoxidize in a bath contamin 2 kg. of sulphocyanide of ammonia and 1 .0 bich'romate of potash, treat for ,4 hour at 30 C; After having added slowly 10 gr. of sulphuric acid of 66? B6. per liter oi 11 not, heat up to C. in V hour, treat for hour at SIS- 0., rinse, neutralize and (II) a. Dyeing.-.--For v10 0 kilos-of wooie;

of ester-salt of leuco-4:4 -dimethyl-6 :'6'-.d1-

chlorothioindigo and 5 kg. of aul hate of ammonia. Enter at 40 .C.,ra'ise to t e boil in hour, boil fol-y hour,- and add 1 of acetic acid. Dye for f urther hourat t e boil un-- t1l the bathis exhausted.

containing 1% of sulphocyanide of ammonia and 1.1% of bichromateof ,4 hour at 30 C. and add 10 gr. of sulphuric acid of 66 Be. per liter of liquor, heat 11 to 85 C in hour, maintain at 85-90 for ,5 hour, rinse, neutralize,'and rinse again. (III) a. Dyeing.-For kilosof woolen material a dyebath is prepared with 1 kg. of estersalt of leuco-3: 4: 8: 9-dibenzpyrene 5:10-quinone and 5 kg. of sulphate of am monia. Enter at 40 0., raise to the boil in owing examples, without limiting potash, treat for b; Developmnt.;-Prepare a fresh bath 0 Example for silk (IV) a. Dyeing-IO k of natural, un weighted silk are dyed col for 4 hour with 20 gr. of estersalt of leuco-2-(-5 7-dibromoindol)-2-anthracene-indi o and an addition of 200 gr. of rongalite C Colour Index, page 364) and 200 gr. of acetic acid of 80% (dyeli uor=800 liters). After having further a ded 200 r. of formic acid of 80%, dye again cold in 10. minutes and raise the tem perature during hour to 80 0., maintain soap with 5 the presence of watersoluble sulp this temperature for hour and rinse.

b'. DeveZopment;--Prepare the oxidizing bath (800 liters) with 200 gr.ofsulphocyanide of ammonia and 60 gr. of bichromate of potash and treat for 4 hour at 30 C. After having slowly added 4 kg. of sulphuric acid of 66 B., heat up in hour to C., treat for hour at 8090 C., rinse, neutralize and gr. of Marseille soap per liter of ii uor for 4 hour near to boiling point.

11 these examples the sulphocyanide of ammonia may be replaced by another soluble salt of hydrosulphocyanic acid, for instance by an alkaline salt of the said acid.

The present process may also be applicable for ester-salts derived from insoluble dyestuffs other than vat-dyestuffs. Ester-salts of such a kind may be bodies which-besides the essential quinone groups (reduced and esterified) as mentioned in the introductioncontain for instance azo roups (see German Patent N 0. 461,500, ritish Patent No. 333,507). It is evident that from such an ester-salt the correspondin stuff can be reformed by acid What I claim is a 1. A process for dyeing animal fibers with esterlike derivatives (ester-salts) of insoluble dyestuffs, containing quinone groups the latter being in a reduced form and esterifiedby applyin said bodies on the fiber and subse uently developing the colour thereon by aci oxidation, said process being characterized by performing this development in salts of hydroacting as buffer oxidation.

ocyanic acid, the latter substance.

subsequently 2. A process for dyeing animal fibers with insoluble dyeby acid oxidation, said process being characterized by adding watersoluble salts of lbaydlrosulphocyanic acid to the acid oxidizing 3. A process for dyeing wool with esterlike derivatives (ester-salts) of insoluble dyestuffs, containing uinone groups-the latter being in a reduce form and esterifiedby applying said bodies on the fiber and subsequently developing the colour thereon by acid oxidation, said process being characterized by adding watersoluble salts of hydrosulphocyanic acid to the acid oxidizing bath. 4. A process for dyeing wool with esterlike derivatives (ester-salts) of insoluble dyestufi's, containing quinone groups-the latter being in a reduced form an esterifiedby applying said bodies on, the fiber and subsequently develo ing the colour thereon by acid oxidation, sai process being characterized by adding sulphocyanide of ammonia to the acid oxidizing bat In witness whereof I have hereunto signed my name this 9th day of December, 1930.

SIGISMUND FUCHS.

esterlike derivatives (ester-salts) of insoluble dyestufi's, containing quinone groups-the latter being in a reduced form and esteri fied-by applying said bodies on the fiber and developing the colour thereon 

